I Didn't Know That: Making Vehicles Explode

When you shoot at fuel tanks, do they blow up like they do in the movies? Or is it all just special effects? I've made my own little film set, got myself a bad guy to apprehend and I intend to find out.

A ha. The evil-doer has concealed himself behind those two cars and I've got to think of a way to flush him out. Some careless so-and-so has left this can of petrol lying around. So I am going to open it, kick it over, and then wait for the fuel to dribble towards it. And then I am going to light it and see if it ignites.

It works! Although interestingly, it's not actually the liquid itself that's burning. It's the petrol vapor that catches alight.

But in the movies all the big crashes and explosions seem to involve trucks and lorries, which run on diesel not petrol. So how would diesel behave in these circumstances? And would the explosions really happen? We'll find out, as soon as I've caught up with that wrong-doer. Come back!

VILLAIN: Oh, you meanie!

JONNY PHILLIPS V/O:

Our baddie's heading for refuge behind those big drums of diesel. Perfect for the next test...

JONNY PHILLIPS:

Now I've got him. He's toast.

All right. So it seems you can't ignite diesel with a naked flame after all. Diesel is heavier and oilier than petrol, and at these temperatures it doesn't give off any vapor that can be ignited.

In fact, diesel doesn't give off flammable vapor until it's at 62 degrees Celsius. So to get it to blow up, I am going to have to resort to one of these.

Surely a bullet into the fuel tank is going to get the diesel burning? Unfortunately, my aim isn't very good, but I can make life easier.

It seems that even if you lead bullets into a tank of diesel it won't explode. The bullets will disperse the diesel into droplets, But without a spark, there's no boom. Unless you use bullets with full metal jackets. Then there's a chance you'll get a spark, and the result will be spectacular.